MONTEVIDEO, URUGUAY – Next year will be a big election year for Latin America, a region where democracy in many countries is only decades young, and where the shadow of corruption stretches wide and long.

Half of the population across the region is being called to cast ballots.

Here are the main points of note concerning the polls in regional economic heavyweights Brazil and Mexico, as well a newly pacified Colombia and troubled Venezuela.

Corruption: the roots of wrath

The Odebrecht scandal – an affair of tentacular graft involving a Brazilian construction firm that is alleged to have paid millions of dollars in bribes to Latin American government officials to secure juicy public contracts – has rocked the region.

It has led to Ecuador’s vice president being imprisoned for six years, and last week nearly resulted in Peru’s president being impeached.

But the scandal is just part of a much bigger picture of corruption, according to Gaspard Estrada, director of the Observatory of Latin America at Paris’s Sciences-Po Institute.

“Corruption phenomena are deeply rooted in the region, and persist,” he said.

“This will have an impact on the next political cycle,” said Fiona Mackie, in charge of Latin America for The Economist Intelligence Unit. The Odebrecht scandal, she added, “is really shaking up the political scene.”

The disheartening multiple cases of embezzlement and personal enrichment by officials in the region have engendered “an impatience now in the electors, because they are so fed up,” Mackie said.

“Elections in Brazil, Colombia, and Mexico will be dominated by voter anger against the political establishment and demand for change, making them hard to predict and opening up room for negative surprises,” the Eurasia consulting firm said in a recent report. “Candidates that better capture this sentiment will be the most competitive, and the risk of negative surprises is high,” as demonstrated by an unexpected surge for the left in a recent Chilean presidential election.

That “should serve as a reminder not to underestimate voter frustration,” it said.

A boon for outsiders

The electoral landscape in Latin America in 2018 is dotted with an increasing number of candidates from outside the political system.

This can be put down to public disgust over the many instances of graft that have “disqualified the traditional political class,” Estrada said.

He spoke of a regional “leadership crisis” and said he fears political outsiders will fuel discourse that undermines democracy, as in Brazil where an extreme-right soldier-turned-politician, Jair Bolsonaro, has emerged as a contender.

Some traditional politicians are presenting themselves as outsiders “because that’s a good thing to do in term of popularity, but they are insiders,” Mackie said. “An outsider needs to ally with a party that has a machinery. You need to have a political movement behind you.”

Eurasia said Mexico “is headed towards its most uncertain and consequential elections in decades on 1 July.”

A left-wing candidate, Andrés Manuel López Obrador, appears best placed for a win at the moment, according to the firm.

A former mayor of Mexico City, López Obrador is aiming for the presidency after a long political career. He has spurned the traditional left-wing PRD party to start the Movement for National Regeneration, known as Morena.

Tilt to the right

The victory of conservative billionaire Sebastian Piñera as president-elect in Chile after a mid-December runoff has confirmed a general right-leaning tilt to the region, building on the stewardship of Mauricio Macri in Argentina, Michel Temer in Brazil and Pedro Pablo Kuczynski in Peru.

But for Estrada, “it’s not really a question of left or right. It’s just the government that had been in place, on the left, had flagged, which encouraged the parties on the right. What happened was a phenomenon of alternation.”

More than political labels, 2018 will be decided by economic issues “because the economy is doing badly,” he said.

“With a few notable exceptions, the policy and economic outlook for Latin America looks set to continue improving in 2018,” Eurasia’s report said. However, political dynamics could determine whether that “positive trend slows or, in some countries, is derailed.”

Eurasia predicted that in Venezuela, the Latin American country with the most severe economic problems, President Nicolás Maduro “will likely remain in office and win the presidential election in a tightly controlled process.”

But, it added: “The government will also likely stumble into default, further complicating an already bleak economic outlook.”